He did not spare the ancient world. He preserved only Noah, a proclaimer of righteousness, along with seven others, when He brought a flood upon the world of the ungodly.
Long ago they disobeyed while God kept waiting patiently, in the days of Noah as the ark was being built. In that ark a few (that is, eight souls) were brought safely through water.
By faith Noah, when warned about events not yet seen, in holy fear prepared an ark for the safety of his household. Through faith he condemned the world and became an heir of the righteousness that comes by faith.
they and every animal according to its kind, and all the livestock according to its kind, and every crawling creature that crawls on the land according to its kind, and every flying creature according to its kind, every bird, every winged creature.
So it will be, if their fathers or brothers come to complain to us, that we will say to them, ‘Grant them graciously for us, because we did not provide each one of them his wife in battle—nor did you give the girls to them, else you would now be guilty.’”